Extensible belt conveyer



Nov. 27, 1951 1. s. EGGLESTON 2,576,217

EXTENSIBLE BELT CONVEYER Filed Feb. 23, 1950 4 Sheets-Sheet l INVENTQR.

ATTORNEY Nov. 27, 1951 l. s. EGGLESTON 2,576,217

EXTENSIBLE BELT CONVEYER Filed Feb. 23, 1950 4 Sheets-Sheet 2 35 as v. m .32

"7,8 any 543/0 ATTORN EY INVENTOR.

Nov. 27, 1951 1. s; EGGLESTON 2,576,217

EXTENSIBLE BELT CONVEYER Filed Feb. 23, 1950 4 Sheets-Sheet 5 INVENTOR.

ATTORNEY Nov. 27, 1951 1. s. EGGLESTON 2,576,217

EXTENSIBLE BELT CONVEYER Filed Feb. 23, 1950 4 Sheets-Sheet 4 an o INVENTOR.

ATTORNEY Patented Nov. 27, 1951 UNITED PATENT OFFICE EXTENSI BL E BELT 'CONVEYER I a Sm th fl gles on, .S Paul, M nn, assignor to Standard Qonveyor Company, North St. Paul, M r a mega of Minnesota Application Februar-y23, 1950, Serial No. 145,755 10 Claims. (Cl. 198--1 39) the tio s o the el u e t ns is ,m

mized.

Aparticularobject is to provide a readily porte. r ve ble an exte o yo av n an endless flexible conveyorbelt, the load carrying reach o wh ch is co t nuou up rt d o plane, smooth, relatively extensible plates or sheet members and the return reach of which is driven by frictional engagement with a powerdriven roller coasting with a grip roller and arranged to minimize both tension in thebelt and bending of the portions of the belt which are under tension.

A further object is to provide in a conveyor of the class described, novel means .for guiding, collecting and storing the relatively slack portions of thebeltduring operation with the load carrying reach partially retracted from its fully extended position.

Other objects will appear and be more fully pointed out in the following specification and claims.

The invention will be best understood by referenoe .to the accompanying drawings which illustrate, by way of example and not for the purpose of limitation, a preferred form of myinvention.

Referring tothe drawings:

Figure -l is a perspective view showing my improved conveyor with portions broken away and with the auxiliary frame in partially extended position;

Fig. 2 is a fragmentary longitudinal section taken approximately .on the line 2--2 of .Fig. 3;

Fig. 3 is a plan view of the conveyor with portions omitted because of limitations of space and with other portions broken away to showdetails otherwise concealed;

Fig. 4 is a perspective view showing certain details of the auxiliary frame and support for the upper'belt reach, with the belt removed and a portion of one of the supporting plates broken away;

Fig. 5 is a cross section taken approximately on the line 5-5 of Figs-'7;

Fig. 6 is a cross section through the auxiliary frame taken approximately 011 the line 6--6 of Fig. 2;

Fig. '7 is a side elevational view showing the conveyor with the auxiliary frame in fully retracted position;

Fig. Bis a cross section taken on the line 8--8 of Fig. '7;

Fig. 9 is a fragmentary, part side elevation and part longitudinal sectional view showing details of the connection between one of the belt sup;- porting members and one of the cross rods of the auxiliary frame, and

Fig. 10 is a fragmentary vertical sectional View taken on the line 0-1 I] of Fig. 2.

My improved conveyor has .a main frame, .the principal members of which comprises substantially horizontally extending longitudinal ,members 55, H and I2 at each side connected by vertical members l3 and laterally extending members It and I5. This frame is made readily portable by supporting it on a pair of main Wheels l6 and a pair of caster type wheels l1. Rigidly connected to the frame members referred. to are sheet metal wall members [8, l9 and 20, a bottom 2 l' and a top member 22, these sheet metal :members defining a housing and receptacle for a slack portion of the conveyor belt and for the belt driving and guiding rollers hereinafter de scribed.

Projecting from one end of the main frame is an auxiliary frame comprising two systems of articulated bars 23 disposed respectively at op posite sides of the conveyor and arranged in lazytong relation to oscillate in vertical planes and to permit a wide range of extension of the conveyor. Bars 24 constituting members of the auxiliary frame are pivotally connected at their upper ends to brackets 25 mounted on the main frame. Pairs of leg members 25 support the auxiliary frame independently of the main frame at suitable intervals and are carried by small wheels 21 mounted on the lower ends of the leg members. Each of the latter members is formed with a vertically elongated slot 28 adapted to slidably receive a horizontally extending rod 29. Each rod 29 connects a pair of the legmembers .together and .pivotally engages selected bars 23. A clamp knob 30 is threaded on each end of each of the rods 39 to permit fastening of the rods at selected elevations in the slots 28, the rods being formed with threaded and reduced end portions which project through the slots 28 to receive the knobs 30. The pair of legs 26 at the outer extremity of the auxiliary frame are rigidly con- 3 nected to bracket plates 3! for supporting a belt guide roller 32. Extending laterally between the legs 25 of each pair is a rod 33 constituting a pivot for the upper extremity of selected bars 23 at each side. A multiplicity of cross rods 34 also connect the systems of bars 23 at opposite sides of the auxiliary frame and afford the several joint pivots; as illustrated.

Extending along the top of the auxiliary frame is a bed structure comprising a plurality of substantially flat, overlapping and relatively extensible plates 35 affording a continuous support for the upper reach of the conveyor belt. The plates 35 are preferably constructed from sheet metal of suitable rigidity and have rear or inner marginal portions 35a. (Fig. 9) which are oifset downward slightly for sliding engagement with the upper surface of the underlying plate. Near its forward or outer edge each plate 35 is connected to the auxiliary frame by means of a pair of U-shaped brackets 36 which brackets engage one of the cross rods 34 or 33, depending on the location of the particular plate with respect to the leg members 26. The several brackets are elongated downward in order to permit limited vertical movement of the front end portions of the plates during the extending and retracting movement of the auxiliary frame. The plates 35 are also supported on the several cross rods 33 and 34 at the top of the auxiliary frame by means of small rollers 31 whichare revoluble on the rods (Figs. 4, 5, 6 and 9). The inner or trailing edge of each of the plates 35 is siidably supported on the plate 35 below, or, in the case of the lowermost plate 35, on the top 22 of the main frame housing.

"An'endless conveyor belt has an upper reach 38 extending from a guide roller 39 at one end of the main frame to the roller 32 at the opposite endof the auxiliary frame. The lower reach ii: of the belt extends from the roller 39 to the upper periphery of a guide roller 4| and thence between a "power-driven drive roller 42 and a coacting pressure roller 43. Except when the auxiliary frame is fully extended, a slack portion of the belt reach 40 is confined in the receptacle carried by the main frame. Another guide roller 44 is mounted on the main frame at its end opposite the roller 4| to support the belt reach 45, which is normally in substantially parallel relation to the upper reach 38 along and substantially from end to end of the auxiliary frame. When this portion of the reach 40 is slack it is supported on a substantially horizontal row of the rods 34 intermediate the upper and lower ends of the members'23 and 24, as indicated in Fig. 2.

My preferred power-driven actuating mechanism for the conveyor belt comprises the coacting rollers 42 and 43 which grip the belt substantially with line contact so that the portion of the belt under tension is not flexed or bent abruptly. These driving rollers are preferably covered with a resilient and somewhat compressible material such as rubber, either natural or artificial, and suitably crowned to retain the belt properly centered laterally of the conveyor. Either one or both of these rollers may be power driven. As shown, the roller 42 is fixed on an axially disposed shaft 45 which projects at one side-of the main frame where a sprocket wheel 46 is fixed on the shaft. An endless chain 41 and a driving sprocket wheel 48 upon which the chain is trained are arranged to drive the sprocket wheel 46. Suitable connections between the sprocket wheel 48 and an'electric motor 43 are provided, including speed reducing mechanism. The motor, speed reducing mechanism and sprocket wheel 48 are supported on a bracket fastened to the frame members IS. The electric motor is preferably of the reversible type so that the conveyor belt may be driven in either direction and is thereby adapted to either deliver or receive load units or material to be conveyed at either end of the upper reach 38.

Belt guide plates 42a, project substantially horizontally from opposite sides of the roller 42 and similar guide plates 43a project horizontally from the roller 43. These plates extend along the rollers closely adjacent thereto and, as best shown in Fig. 10, are supported at their ends on the bars 42b and 4319 which are fastened to the side walls 20. The reach 40 of the belt is guided to and from the bight of the rollers 42, 43 between the plates 42a. and 43a which are arranged to deflect loose folds of the belt from the vicinity of the bight.

To insure the free passage of the lower reach of the belt out of the bin confining the slack folds of the belt, I provide baiiies Ma and 44a, one at each end of the bin. These baffles extend obliquely downward from the top member 22 toward the upper peripheries of the rollers 4i and 44 respectively and are spaced from the rollers just sufficiently to allow (for the free passage of the belt to and from the bin. The lower edge of each baffle is preferably provided with a rounded surface such as that afforded by a rod of circular cross section which is welded to the bafile. The inside angle of each bafile to the horizontal is preferably about l051l0 so that any'slack fold of the belt which may tend to follow the outgoing reach is deflected back into the lower part of the bin.

To support the auxiliary frame entirely on the main frame when in a substantially fully retracted position, such as that indicated in Fig.

' 7, a pair of rails 50 are mounted on projecting portions of the main frame members In to project beneath the auxiliary frame and pairs of small rollers 5| are mounted on the legs 26 in approximate alignment with these rails. Inclined end portions 52 are formed on the rails to pass beneath the rollers 5| and to guide the latter to the upper surfaces of the rails. The legs 26 pass between the rails 59 and the rollers 21 are lifted slightly above the floor supporting the conveyor when the auxiliary frame is fully retracted. When in this fully retracted position shown in Fig. 7 the conveyor is unusually compact and the entire structure may be moved about on the wheels l6 and H with ease. Projecting from the bracket plates 3| at the outer end of the auxiliary frame is a horizontally extending handle 53 and at the opposite end of the main frame a similar handle 54 projects to facilitate movement of the auxiliary frame to and from the various extended and retracted positions as well as movement of the entire conveyor structure to and from any place where it is to be used.

In operation, the conveyor belt may be driven by frictional engagement with the driving rollers receptacle -or bin carried by the mainframe :is automatically collected and stored in one or more folds, as indicated at 40a in Fig. 2. When driven in the opposite direction, any excess slackupors tion of the belt will extend in one or more folds between and below the rollers 41 and 42, as indicated in broken lines at 48b and the reach .40 at the opposite side of the driving roller 42 will extend substantially as indicated by the broken lines 400 in Fig. 2. By this arrangement, I mini,- m-ize bending of those portions, of the belt which are under tension and thereby save much power which would otherwise be wasted in friction and fiexingof the belt, while-prolonging the useful life of the belt and its driving and guiding mechamsm.

The guide plates 42a and 43a prevent the slack folds of the belt from being fouled between .or around the rollers 42 or 43 and the bafiies Ma and Ma, prevent fouling of the slack folds in the exit slots by frictional contact with the portion of the belt leaving the bin. Any slack fold which might tend to follow this portion of the belt over the periphery of either the rollers ll or 44 is stripped off by the bafile 4 la or 44a, thus insuring that the belt runs freely out of the bin irrespective of the number of folds that may be confined in the bin in sliding engagement one with another. It will be evident that guide plates 52a and 43a perform their guiding function irrespective of the direction of travel of the belt and the baffles Ma and lila perform their function at the i exit openin at one end or the other of the bin, depending on the direction of travel of the belt.

To change the effective length of the conveyor, either when the belt is in operation or when the power is shut off, the clamp knobs 36 are merely turned to free the rods 29 for vertical movement in the slots 28 and then the auxiliary frame may be extended or retracted by manipulation of the handles 53 or 54, or both of them, as required. The adjusted effective length of the conveyor may then be fixed by tightening the clamp knobs 30. The upper reach 38 of the conveyor belt may be operated in the substantially horizontal position shown in the drawings or at various inclines or declines by merely supporting the several pairs of leg members 26 at the desired elevations, The entire auxiliary frame, including the plates 35, is sufiiciently flexible vertically to permit a fairly wide range of variations in angle of incline relative to the main frame.

By merely adding pairs of legs 26 with connecting sections of articulated bars 23 and additional plates 35, a conveyor of any desired length may be provided. For example, a long conveyor adapted to be extended instantaneously to lengths up to fifty feet or more may be retracted to afford a readily portable structure less than ten feet long.

My improved conveyor is adapted for a wide range of uses. It is particularly useful in the loading of large trucks, railway cars and other vehicles. For such use the main frame may be located exteriorly of the vehicle and the auxiliary frame may be extended through the door of the vehicle and supported on the leg members 26 at various distances from the main frame and door for carrying load units to or from any desired point within the vehicle or car.

The present application is a continuation in part of my application Serial No. 777,644, filed October 3, 1948?, now abandoned.

Having described my invention, what I claim as new and desire to protect by Letters Patent is:

IL A conveyor comprising, a ,normally statiom ary main frame, a relatively long, extensible and retractile auxiliary frame connected at its inner end to said main frame, means for supporting the outer end ,of :said auxiliary "frame in variously extended and retracted positions relative to :the anain frame, an endless conveyor belt, means supporting the upper reach of :said belt for operation along the top of said main .and auxiliary frames, .means carried :by said auxiliary frame for supporting the lower :reach of said belt, a pair of hell; ,driving rollers .carriedby saidmai-n frame and arranged to engage opposite surfaces of the lower :reach of the belt and a receptacle extending at a lower elevation than said belt driving rollers and having wall members disposed :to guide ,and confine slack folds of said belt in sliding .contactone with another whenthe auxiliary frame :is in retracted and partially extended positions.

-2. A conveyor as defined in claim 1 in which said :means for supporting the upper reach of said belt comprise -a plurality of slidably over.- lapping plates affording a continuous support for the belt along the top of said auxiliary frame.

3. A conveyor as defined in claim 1 in which said means for supporting the upper reach of said belt comprise a plurality of slidably overlapping plates affording a continuous support for the belt along the top of said auxiliary frame, said auxiliary frame comprising systems of articulated bars disposed in lazy-tong relation one to the others along the respective sides of the conveyor, laterally extending rods connecting said systems together and means connecting the outer end portion of each of said plates to a selected laterally extending rod whereby said plates are actuated one relative to another when the auxiliary frame is extended or retracted.

4. A conveyor as defined in claim 1 wherein belt guide members are disposed to extend in spaced relation one to the other at a side of and adjacent to the peripheries of said belt driving rollers respectively to guide the lower reach of the belt to the bight of said rollers.

5. A conveyor as defined in claim 1 wherein fixed guide plates are disposed in spaced relation one to another and substantially horizontally adjacent to the peripheries of said belt driving rollers and approximately at the elevation of the axis thereof to guide the lower reach of the belt to and from the bight of said rollers.

6. A conveyor as defined in claim 1 in which said receptacle is formed with a horizontally elongated outlet opening for said belt and means for guiding the belt through said opening comprising a roller extending along the lower side of said opening to support the belt and a bafile extending downward toward the upper periphery of said roller and having a lower edge defining the upper side of said opening.

'7. A conveyor as defined in claim 1 in which said receptacle is provided with a horizontally i elongated outlet opening for said belt and means for guiding the belt through said opening comprising, a roller extending along the lower side of said opening to support the belt and a fixed baffle plate extending obliquely downward toward the upper periphery of said roller and having a rounded lower edge defining the upper side of said opening.

8. A conveyor comprising, a normally stationary main frame, wheels for portably supporting said frame on a supporting surface, a relatively long, extensible and retractile auxiliary frame connected at one end to said main frame, a plurality of pairs of leg members for supporting the auxiliary frame in variously extended positions relative to the main frame, a pair of substantially horizontally disposed rails projecting from an end of said main frame at an elevation above said supporting surface and beneath said auxiliary frame for supporting said leg members on the main frame when the auxiliary frame is in fully retracted position, an endless conveyor belt, means supporting the upper reach of said belt for operation along the top of said main and auxiliary frames, means carried by said auxiliary frame for supporting the lower reach of said belt, driving means for said belt carried by said main frame and means for receiving and collecting slack folds of said belt when the auxiliary frame is in retracted and partially retracted positions relative to the main frame.

9. A conveyor comprising, a normally stationary main frame, a relatively long, extensible and retractile auxiliary frame connected at its inner end to said main frame, means for supporting the outer end portion of said auxiliary frame in variously extended and retracted positions relative to the main frame, an endless conveyor belt, means carried by said auxiliary frame for supporting the lower reach of said belt, reversible driving means for said belt carried by said main frame and a bin for receiving slack folds of said belt carried by said main frame and having walls disposed to guide and confine slack folds of the belt in sliding contact one with another when the auxiliary frame is in retracted and partially extended positions.

10. A conveyor according to claim 9 in which said means for driving the belt comprise a pair of belt driving rollers in gripping engagement with opposite surfaces of the lower reach of the belt and wherein said bin for receiving slack folds of the belt extends at a lower elevation than said belt driving rollers.

IRA SMITH EGGLESTON.

No references cited. 

